Asked by:

Failure to establish P2P Call

Question

I have been trying to solve this problem for two days but cannot get to the root of it.

Problem:

Two users from the same company, one is external on a lync client on his pc and the other inside the company on a lync client on his pc, when home user initiates a audio/video call nothing happens for work user, they dont even get notified of the call.

What does work:

Both users outside of the network, both users inside of the network, desktop sharing and a conference audio/video with one user outside and one user inside.

Environment:

We have two edge servers and one enterprise pool which contains two enterprise servers. While testing I shut down one edge server and one front end server to make troubleshooting easier.

408 Request Timeoutms-diagnostics: 5026;reason="The request was sent to the callee's client endpoints but no further response was received.";AppUri="httpRequestUri: sip:requested.user@domain.comFrom: sip:requesting.user@domain.com;tag=c238bcf642To: sip:requested.user@domain.com;tag=45EA2C3769C60367059330289D9E66D6Call-ID: b03ea1dc6ae04299aeb771fa7043bdfbContent-type: multipart/alternative;boundary="----=_NextPart_000_0244_01CD246B.94D6D420";call-type=audiovideo

408 Request Timeoutms-diagnostics: 5026;reason="The request was sent to the callee's client endpoints but no further response was received.";AppUri="httpRequestUri: sip:requested.user@domain.comFrom: sip:requesting.user@domain.com;tag=c238bcf642To: sip:requested.user@domain.com;tag=45EA2C3769C60367059330289D9E66D6Call-ID: b03ea1dc6ae04299aeb771fa7043bdfbContent-type: multipart/alternative;boundary="----=_NextPart_000_0244_01CD246B.94D6D420";call-type=audiovideo

408 Request Timeoutms-diagnostics: 5026;reason="The request was sent to the callee's client endpoints but no further response was received.";AppUri="httpRequestUri: sip:requested.user@domain.comFrom: sip:requesting.user@domain.com;tag=c238bcf642To: sip:requested.user@domain.com;tag=45EA2C3769C60367059330289D9E66D6Call-ID: b03ea1dc6ae04299aeb771fa7043bdfbContent-type: multipart/alternative;boundary="----=_NextPart_000_0244_01CD246B.94D6D420";call-type=audiovideo

408 Request Timeoutms-diagnostics: 5026;reason="The request was sent to the callee's client endpoints but no further response was received.";AppUri="http%3A%2F%2Fwww.microsoft.com%2FLCS%2FDefaultRouting";client-forks="1";source="frontend.fqdn.net";OriginalPresenceState="0";CurrentPresenceState="0";MeInsideUser="No";ConversationInitiatedBy="0";SourceNetwork="0";RemotePartyCanDoIM="No"

408 Request Timeoutms-diagnostics: 5026;reason="The request was sent to the callee's client endpoints but no further response was received.";AppUri="http%3A%2F%2Fwww.microsoft.com%2FLCS%2FDefaultRouting";client-forks="1";source="frontend.fqdn.net";OriginalPresenceState="0";CurrentPresenceState="0";MeInsideUser="No";ConversationInitiatedBy="0";SourceNetwork="0";RemotePartyCanDoIM="No"

</Data> </EventData></Event>

The most obvious error that stands out is the 5026;reason="The request was sent to the callee's client endpoints but no further response was received error but we ensured that port 443 and 3478 is open.

All replies

Hi, I have not read the logs, but normal this problems comes from micsonfuguration of firewall or edge server. Be sure that all ports are open internal and external like described in the Lync Workflow poster.

Thanks for the response. We have ensured that all ports are open where firewalls are. We did traces and did not see anything being blocked on any firewalls that are in the way and the Edge servers has the correct static routes.

Like I said, with a user outside and a user inside, conferencing works, desktop sharing and file transfers works, its just p2p.

When one user is internal and one user is external , they will attempt peer to peer. The external user will hit TCP 5061 to the Access Edge Server and will be provided with either UDP 3478 or TCP 443 for the Audio/Video Edge. UDP 3478 is preferred even if
the connection test for TCP 443 and UDP 3478 were successful in testing. Because this is technically peer to peer, the internal user will NOT connect to the MCU on the Front End but will instead connect directly to the A/V Edge Server’s Internal NIC over UDP
3478 or TCP 443 as well. The Front End A/V MCU will not be used in this scenario. When you add a 3rd person to the conversation, the external user will connect to the Front End Server’s A/V MCU in which the A/V Edge will proxy this data for the
user, and the internal users will connect to the Front End A/V MCU instead of the Internal Edge NIC.

You can do a netstat -an to see your server listening on UDP 3478 and utilize netcat which can attempt telnet to UDP by using netcat -u host 3478.

No resolution. We allowed all traffic and it was still not working. We decided that we will just just the meet me now option to move it p2p to a conference which moves onto the servers as a work around.

Thanks for that info. It seems like i will have to find a resolution to this after all due to a 3rd party application we might be using. I did a call with an internal person which failed as expected and when I looked at the monitoring server
i found this error and the part that stands out that is wrong is in bold:

Microsoft is conducting an online survey to understand your opinion of the Technet Web site. If you choose to participate, the online survey will be presented to you when you leave the Technet Web site.